Glycidyl carbamate functional oligomers and polymers can be prepared by the reaction of a polyfunctional isocyanate compound and glycidol. See, e.g., Doss, R. C. U.S. Pat. No. 3,440,230, 1969; Freiter, E. R. U.S. Pat. No. 4,020,034, 1977; Ohrbom, W. H., December, T. S., U.S. Pat. No. 6,849,337, 2005; and Hoeschele, G. K. U.S. Pat. No. 4,069,208, 1978. Alcohol-modified glycidyl carbamate resins are described by PCT Application PCT/US08/78,112, filed Sep. 29, 2008. These document as well as others cited below are incorporated by references.
Glycidyl carbamate functional compounds will undergo self-crosslinking at elevated temperatures (ca. 150° C.). See, e.g., Peter A. Edwards, Grant Striemer, Dean C. Webster, “Synthesis, Characterization, and Self-Crosslinking Of Glycidyl Carbamate Functional Resins,” Prog. Org. Coat, 57. 128-139 (2006).
Glycidyl carbamate functional oligomers can be crosslinked with multifunctional amines at either ambient or elevated temperatures to form crosslinked coatings with a good combination of properties. See, e.g., Peter A. Edwards, Grant Striemer, Dean C. Webster, “Novel Polyurethane Coating Technology through Glycidyl Carbamate Chemistry,” JCT Research, 2(7), 517-528 (2005).
Glycidyl carbamates have been described in the synthesis of glycidyl terminated polyurethane resins. See Chen, et al., J. Appl. Polym. Sci., 51, 1199-1206 (1994). In Chen, linear polymers made by reacting an excess of a diisocyanate with a polyol, then reacting the residual isocyanate groups with glycidol to form the glycidyl carbamate end groups. The polymers were then crosslinked with amines and their properties as adhesives evaluated.
Epoxy resins modified with glycidyl terminated polyurethanes was disclosed in Hsia, et al., J. Appl. Polym. Sci., 52, 1137-1151 (1994). In Hsia, the glycidyl terminated polyurethanes are linear aromatic polymers terminated with glycidyl carbamate groups, similar to those described in Chen. A bisphenol-A glycidyl ether epoxy resin was used.
However, no reports of the corrosion performance of coatings prepared from glycidyl carbamate functional compounds have been found in the literature. Thus, what is needed in the art is a way of improving the corrosion resistance properties of these glycidyl carbamate functional compounds, particular when such compounds are used as coating compositions on substrates. This invention answers that need.